Among
the post-lithium-ion batteries, rechargeable dual-ion batteries
(DIBs) have bright opportunities for the development of cheap and
safe batteries possessing a good electrochemical performance. The
DIBs with pure ionic liquid (IL) electrolytes featuring a high voltage,
sustainability, and environmental friendliness have received attention
from researchers. Owing to intercalation/deintercalation of large
size IL cations, the conventional dual-graphite batteries (DGBs) have
suffered from severe volume expansion, thus limiting the overall reversibility
of the DGBs. Herein, we have modeled two DIBs, introducing an organic
cation-intercalated polycyclic aromatic hydrocarbon anode (coronene)
coupled with a graphite cathode and a DGB in the other case. Pyrrolidinium-based
IL, N-butyl-N-methyl pyrrolidinium
chloride (BMP-Cl) with the AlCl3 salt has been employed
as an electrolyte. Applying the first-principles calculation, we have
investigated the systematic intercalation of the BMP cation into the
coronene and graphite anodes. The BMP-intercalated graphite anode
shows a higher binding energy (2.36 eV) compared to that of the coronene
anode (1.71 eV). In the fully charged state, a calculated discharge
voltage of 3.1 and 3.05 V and a maximum capacity of 116 and 130 mA
h g–1 have been observed for the graphite coronene
dual-ion battery (GCDIB) and DGB, respectively. However, the percentage
of volume expansion of the graphite anode is higher (148%) compared
to that of the coronene anode (53%) upon a full intercalation of BMP
cations, indicating more exfoliation-prone nature of graphite compared
to coronene. The density of states and Bader charge analysis reveal
that the BMP cation is intercalated successfully, indicating a reduction
of electrode materials during the charging process. Furthermore, we
have explained the merits of choosing the AlCl4 anion compared
to other commonly used anions such as TFSI in DIBs. These results
support a clear understanding of BMP cation intercalation into both
coronene and graphite anodes and motivate the fabrication of a new
class of low-cost organic anode DIBs with an optimum electrochemical
performance.